This invention relates to a beverage brewing filter structure for retaining a brewing substance or a combination of a filter and a brewing substance for infusion with heated water to produce a liquid brewed beverage.
Many beverage brewing filter structures define a frame to support and separate a disposable brewing filter containing a portion of brewing substance disposed therein from internal walls of a beverage brewing funnel. These beverage brewing filter structures must retain the brewing filter and brewing substance so as to space them away from the funnel walls to define a passage therebetween, thereby permitting the liquid brewed beverage to drain from the brewing filter, into the passage and through an aperture formed in the bottom of the funnel. Other beverage brewing filter structures are also formed where the filter structures and the brewing funnels are one in the same.
Typically, filter structures are formed to fit the shape of brewing funnels and to support most mass-produced brewing filters (i.e., disposable paper filters). Such filter structures generally have a base with walls protruding from the base at an obtuse angle, forming an opening with a larger diameter than that of the base. Thus, when the brewing substance is situated within the brewing filter, the brewing filter generally conforms to the shape of the filter structure. This design, however, does not optimize extraction of the brewing substance because when the hot water infuses the brewing substance, the brewing substance directly above the base becomes spent very quickly whereas the brewing substance proximally located along the angled walls is hardly spent at all. Thus, not all of the brewing substance is infused substantially the same amount, potentially leaving an uneven extraction of the brewing substance.
Also, most filter structures have a base that is angled downward so that all the liquid brew flows toward a center point of a brewing filter that is rested in the filter structure. The liquid brew then drains from the brewing filter at this center point into the brewing funnel. This single drainage point design, however, causes the brewing substance near the center point to be thoroughly saturated and perhaps over infused, thus potentially creating additional uneven extraction of the brewing substance and making for a bitter flavor in the brewed liquid.